Telephone lines, which are carried by electrical conductors known as tip ring wire pairs, originate from a central office (CO) and are aggregated at a particular point in a building prior to being distributed and connected to various types of telephone equipment, such as, for example, telephones, fax machines, modems etc., in the building. The tip ring wire pairs, which generally enter the building as part of a multi-conductor cable, are connected to a junction box known as, for example, a building entrance protector (BEP), or network interface unit (NIU). Within the junction box, the individual telephone line tip ring wire pairs are separated from the cable, individually connected to a connector block, and made available for further electrical connection and distribution.
The connector block, also known as insulation displacement connector (IDC) block, may be the ubiquitous punch down connector block, also known as a 66-type connector block, or the tool-less insulation displacement connector block utilizing push cap connectors, such as that described in U.S. Pat. No. 4,913,659 dated Apr. 3, 1990, the entire disclosure of which is incorporated herein by reference. Such a connector block is commercially available under the product designation SC99 from Lucent Technologies Inc.
The tool-less insulation displacement connector block includes an IDC type connector on one side of the connector block having a terminal disposed therein for connecting a tip ring wire thereto. Opposite each IDC connector on the other side of the connector block is a matching, electrically connected wire wrap terminal, such that a wire connected on the wire wrap side may be connected to another wire coupled to the IDC side of the block. The tip and ring wires that are coupled to the IDC connector are strain relieved by the compression of the terminal within the IDC that holds the bare wire which has been stripped of its insulation layer.
A significant drawback of the prior art IDC connectors is that the terminal in the connector provides minimal strain relief on the inserted tip ring wire. As a result, when a pulling force is applied to the tip or ring wire, the wire can be dislodged from the terminal and disconnected from the connector.
Another drawback encountered in prior art IDC connectors is the need to trim excess wire that protrudes through and beyond the cap once the wire is secured within the IDC. These trimmings are generally short, difficult to handle wire lengths that can easily fall into the BEP or NIU or other associated equipment, posing the risk of causing short circuits or other malfunctions.
Thus, it is desirable to provide a better strain relief mechanism for wires connected to an IDC connector in a connector block to prevent the tip ring wires from being disconnected from the connector in response to a pulling force, and to eliminate hazardous wire trimmings.